High voltage switch



Sept. 3, 1957 o. LEOPOLD 2,895,305

HIGH VOLTAGE SWITCH Filed March 2e, 1954 Inventor.'

OTT o LE o P 01.0

United States Patent C HIGH VOLTAGE SWITCH Otto Leopold, Lohfelden, near Kassel, Germany, assigner to Licentia Patent-Verwaltungs-G. m. b. H., Hamburg, Germany Application March 26, 1954, Serial No. 419,013 Claims priority, application Germany March 31, 1953 9 Claims. (Cl. Nil- 148) This invention relates to a high voltage switch and more particularly to an improved high voltage switch of the type utilizing a jet of pressurized gas to extinguish the high voltage arc formed upon the opening of the switch.

it is an object of the present invention to provide a high voltage switch usable for both heavy and ordinary loads which requires a minimum amount of pressurized gas to extinguish the high voltage arc.

In accordance with the invention there is provided a switch arm arrangement including a contact means and a switch arm means having a contact end portion and movable from an engaging position in which said contact end portion engages the contact means to a retracted position in which the contact end portion is spaced from the contact means. During this movement an arc is formed. There is also provided a pressurized gas conduit means formed with an open end adjacent the contact means and the switch arm means, the conduit means having relatively close to its open end a portion of substantially restricted cross-sectional configuration. Because of this restricted portion, the gas in the conduit beyond the restricted portion builds up in pressure. When an are is formed during the movement of the switch arm means from its engaging position to its retracted position, the arc blocks the open end of the conduit means and the gas within the conduit means between the open end and the restricted portion thereof rapidly approaches the pressure of the gas beyond the restricted portion. The result is that very high pressure is available for quickly extinguishing the high voltage arc.

In a preferred embodiment of the invention the contact means is formed as a flaring aperture in a conductive plate and the contact end of the switch arm means engages this aring portion. Beyond the aperture and spaced therefrom is located an arcing electrode so that upon opening the switch, the arc formed between the contact end of the switch arm and the contact means is blown through the aperture until it terminates at the arcing electrode and is finally extinguished.

The novel features which are considered as characteristie for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specic embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a cross-sectional View of an arc extinguishing chamber of a high voltage switch in accordance with the invention;

Y Fig. 2 is a view along line A-A of Fig. l;

Fig. 3 is a side view of the arrangement shown in Fig. l; and

Fig. 4 is a top view of the arrangement shown in Fig. l.

ln the gures, like numerals designate like elements.

Referring now to Figs. 1 4 there is shown an are extinguishing chamber housing 1 formed of an insulating Patented Sept. 3, 1957 material. Within the housing is located a guide cylinder 2 formed of a conductive material coaxial about a movable switch arm 3. A current supply terminal (not shown) is connected to the guide cylinder 2 and the current is fed from the guide cylinder 2 to the switch arm 3 through contact means 4 which is in slidable engagement with said switch arm. The switch arm is movable from a position in which it engages the contact means 5 to a position (shown) retracted from the contact means. This movement may he accomplished by directing a jet of pressurized gas against a portion (not shown) of the switch arm means or by mechanical means well known in the art. When the switch is closed, the current is carried from the switch arm 3 to the contact means 5, through the spacer pins S and the top plate 7 to the terminal 6.

The pressurized gas for extinguishing the arc formed upon opening the switch is carried by pressurized gas conduit 10 which is concentrically arranged about the guide cylinder 2. The pressurized gas moves in the direction indicated by the arrows. As can be seen, close to the open end of the pressurized gas conduit the guide cylinder 9 is made of increased size in order substantially to restrict the cross-sectional configuration of the conduit 10. In a preferred embodiment of the invention, the size of the restricted portion of the pressurized gas conduit is made about one-half that of the remainder of the conduit. The restricted portion of the conduit causes gas pressure to build up in section 18 of the conduit so that this section can be though of as a high pressure gas chamber.

The contact means 5' is formed with a conically haring portion 12 which the oblique portion 13 of the switch arm engages when the switch is closed. Upon opening the switch the arc which forms is blown until it extends between portions 14 and 15 of the contact means and switch arm means, respectively, and the end terminating at portion 14 is then blown to the arcing electrode 16. ln order to lengthen the life of the switch parts 14, 15 and 16, they are made of a highly resistant metal such as tungsten or titanium. The portion 17 of the switch chamber wall 1 which is close to the arcing area is formed of a heat resistant material.

In operation, upon opening of the switch, an arc forms which blocks the open end of the conduit 1G. When this occurs, the gas pressure in the portion 19 of the conduit very rapidly builds up until it equals that of the gas in the portion 18 of the conduit. This occurs very rapidly, in only a small fraction of the time during which strong arcing occurs. This very high pressure causes the gas to be directed against the side of the arc and blow it very quickly rst so that it extends between portions l5 and 14 and then so that it extends between portion 15 and arcing electrode 16. The arc is shortly thereafter extinguished. Thus, it is possible using only the normal supply of pressurized gas, quickly and surely to extinguish arcs at both high loads and ordinary loads. With the ingenious arrangement described, it is possible to increase the spacing required at the open end of the gas conduit for operation at high loads without enlaring the entire gas conduit and therefore even at high loads it is possible to utilize normal gas consumption.

The noxious gases formed during the opening of the switch and the subsequent extinguishing of the arc are carried through the hollow center of the switch arm to an outlet means (not shown) and also through the aperture in the contact means 5 and out of the mufer openings 11 located in the wall joining member 5 and plate 7.

Although in the description above the invention has been applied to an arrangement in which only one switch arm is movable it is to be understood that the invention is equally applicable to devices having a plurality of movable switch arms. It is also applicable to the case where arcs are formed between more than two electrodes.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of switches diifering from the types described above.

While the invention has been illustrated and described as embodied in a high voltage switch including a kfixed Contact means and a movable switch arm, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the Vspirit of the present invention.

Without fur-ther analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential character'i'stics of the generic or specilic aspects of this invention and, therefore, such adaptations should and are intended to' he comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. AA high voltage switch arrangement comprising, in combination, Contact means; switch arm means including a contact end portion, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said Contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; and pressurized gas conduit means formed with an open end adjacent said contact means and said contact end of said switch arm means and having relatively close to said open end a fixed portion of substantially constricted crosssectional configuration to define, in said conduit means, a downstream portion between said constricted portion and said open end thereof and an upstream portion on the other side of said constricted portion, said downstream portion gradually diverging from said constricted portion to said open end of said conduit means so that when an arc is formed during movement of said switch arm means from said engaging position to said retracted position it at least partially blocks said open end of said conduit means, and the pressure of the gas within the downstream portion of said conduit means approaches the pressure of the gas in said upstream portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc.

2. A high voltage switch arrangement comprising, in combination, contact means; switch arm means including a contact end portion, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; and pressurized gas conduit means coaxial with said switch arm means and formed with an open end adjacent said Contact means and said contact end of said switch arm means and having relatively close to said open end a iixed portion of substantially constricted cross-sectional configuration to define, in said conduit means, a downstream portion between said constricted portion and said open end thereof and an upstream portion on the other side of said constricted portion, the pressure of the gas owing through said conduit means being substantially larger in said upstream portion thereof than in said downstream portion, and said downstreamy portion gradually diverging from said constricted portion to said openiend of said conduit means sonthat, when` an arc is formed during movement of said switch arm means from said engaging position to said retracted position it at least partially blocks said open end of said conduit means, and the pressure of the gas within the downstream portion of said conduit means approaches the pressure of the gas in said upstream portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc.

3. A high voltage switch arrangement comprising, in combination, contact means; switch arm means including a contact end portion, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; and pressurized gas conduit means formed with an open end adjacent said contact means and said contact end of said switch arm means and having relatively close to said open end a portion having a cross-sectional conguration of approximately one-half the size of the ecross-sectional configuration of the remainder of said conduit means to define, in said conduit means, a downstream portion between said constricted portion and said open end thereof and an upstream portion on the other side of said constricted portion so that the pressure of the gas flowing through said conduit means in said upstream portion is at least twice the pressure of the gas in said downstream portion thereof, said downstream portion of said conduit means gradually diverging from said constricted portion thereof to said open end thereof.

4. A high voltage switch arrangement comprising, in combination, contact means; switch arm means including a Contact end portion, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said contact means to a retracted position in which said Contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; arcing electrode means aligned with said contact means and said contact end portion and spaced further from said switch arm means than from said contact means and pressurized gas conduit means formed with an open end adjacent said contact means and said contact end of said switch arm means and having relatively close to said open end a constricted portion having a cross-sectional configuration of approximately one-half the size of the cross-sectional configuration of the remainder of said conduit means, said conduit means gradually diverging from said constricted portion thereof to said open end thereof so that when an arc is formed during movement of said switch arm means from said engaging position to said retracted position it at least partially blocks said open end of said conduit means, and the pressure of the gas within said conduit means between said open end thereof and the constricted portion thereof approaches the pressure of the gas in said conduit means beyond the constricted portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc, said gas exerting pressure against said arc and blowing the same until said arc terminates at said arcing electrode, said arc finally being extinguished by said gas.

5. A high voltage switch arrangement comprising, in combination, contact means including a portion thereof formed of a conductor which is highly resistant to the action of a high voltage arc; switch arm means including a contact end portion formed of a conductor which is highly resistant to the action of a high Voltage arc, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; arcing electrode means aligned with said contact means and said contact end portion and spaced further from said switch arm means than from said contact means and pressurized gas conduit means formed with `an open end adjacent said contact means and said contact end of said switch arm means and having relatively close to said open end a fixed portion of substantially constricted cross-sectional configuration, said conduit means gradually diverging from said fixed portion thereof to said open end thereof so that when an arc is formed during movement of said switch arm means from said engaging position to said retracted position it at least partially blocks said open end of said conduit means, and the pressure of the gas within said conduit means between said open end thereof and the fixed constricted portieri thereof approaches the pressure of the gas in said conduit means beyond the fixed constricted portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc, said gas exerting pressure against said arc and blowing the same until said arc terminates at said arcing electrode, said arc finally being extinguished by said gas.

6. A high voltage switch arrangement comprising, in combination, contact means comprising a metal plate formed with an aperture -therein opening in opposite faces of said plate and flaring outwardly toward one of said faces of said plate; switch arm means including a contact end portion adapted to engage the flaring portion of said contact means, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; arcing electrode means aligned with said aperture in said metal plate and spaced further from said switch arm means than said metal plate; and pressurized gas conduit means concentrically arranged about said switch arm means and formed with an open end adjacent said contact means and said contact end of said switch arm means, and having relatively close to said open end a fixed portion of substantially restricted cross-sectional configuration so that when an arc is formed during the movement of said switch arm means from said engaging position to said retracted position it at least partly blocks said open end of said conduit means, and the gas within said conduit means between said open end thereof and the fixed restricted portion thereof approaches the pressure of the gas in said conduit means beyond the restricted portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc, said gas exerting pressure against said arc proportional to the size thereof and blowing the same through said aperture in said metal plate until said arc terminates at said arcing electrode, said arc finally being extinguished by said gas.

7. A high voltage switch arrangement as set forth in claim 6 wherein said contact means, said contact end portion of said switch arm means and said arcing electrode all include at least a portion thereof formed of a metal which is highly resistant to the action of a high voltage arc.

8. A high voltage switch arrangement comprising, in combination, contact means comprising a metal plate formed with an aperture therein opening in opposite faces of said plate and Haring outwardly toward one of said faces of said plate; switch arm means including a contact end portion adapted to engage the flaring portion of said contact means, said switch arm means being movable from an engaging position in which said contact end portion thereof engages said Contact means to a retracted position in which said contact end portion thereof is spaced from said contact means, whereby a high voltage arc is formed upon movement of said switch arm means from said engaging position to said retracted position; arcing electrode means aligned with said aperture in said metal plate and spaced further from said switch arm means than said metal plate; and pressurized gas conduit means concentrically arranged about said switch arm means and formed with an open end adjacent said contact means and said contact end of said switch arm means, and having relatively close to said open end a portion having a crosssectional configuration of approximately one-half the size of the cross-sectional configuration of the remainder of said conduit means so that when an arc is formed during the movement of said switch arm means from said engaging position to said retracted position it at least partly blocks said open end of said conduit means, and the gas within said conduit means between said open end thereof and the restricted portion thereof approaches the pressure of the gas in said conduit means beyond the restricted portion thereof at a rate substantially proportional to the amount said open end is blocked by said arc, said gas exerting pressure against said arc proportional to the size thereof and blowing the same through said aperture in said metal plate until said arc terminates at said arcing electrode, said arc finally being extinguished by said gas.

9. A high voltage switch arrangement comprising, in combination, a housing having an `arc extinguishing charnber; at least two cooperating contacts mounted in said chamber, at least one of said contacts being movable from an engaging position to a retracted position in which said contacts are spaced from each other, whereby a high voltage arc is formed upon movement of said contacts; and pressurized gas conduit means surrounding at least one of said contacts and being formed with an open end adjacent the space between said contacts in said retracted position thereof, said conduit means having relatively close to said open end thereof a fixed portion of substantially constricted cross-sectional configuration of such size that when gas is flowing `through said conduit means, the gas pressure produced on one side of said constricted portion thereof is substantially larger than the gas pressure produced on the other side of said constricted portion, said conduit means gradually diverging from said fixed portion thereof to said open end thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,290,004 Thommen July 14, 1942 2,447,674 Strom et al Aug. 24, 1948 2,452,221 Brock Oct. 26, 1948 2,517,136 Schneider Aug. l, 1950 2,643,315 Forwald June 23, 1953 FOREIGN PATENTS 355,133 Great Britain Aug. 20, 1931 660,394 Germany May 21, 1938 

